Stephen Hillenburg, the creator of the iconic “SpongeBob SquarePants” has died. He was 57.

Hillenburg was a 1984 graduate of Humboldt State University. He earned a degree in natural resources planning and interpretation, according to the university.

“His infectious love of marine biology lives on,” the university tweeted this morning.

Hillenburg’s show, “SpongeBob SquarePants” has aired on Nickelodeon since 1999. Hundreds of episodes of the show have aired since then. Features in the show are often credit as being inspired by local businesses and areas around Humboldt County.

“We are incredibly saddened by the news that Steve Hillenburg has passed away following a battle with ALS,” Nickelodeon said in a statement. “He was a beloved friend and long-time creative partner to everyone at Nickelodeon, and our hearts go out to his entire family. Steve imbued ‘SpongeBob SquarePants’ with a unique sense of humor and innocence that has brought joy to generations of kids and families everywhere. His utterly original characters and the world of Bikini Bottom will long stand as a reminder of the value of optimism, friendship and the limitless power of imagination.”

Hillenburg revealed last March that he had diagnosed with ALS.

Born in Lawton, Oklahoma and raised in Anaheim, Hillenburg became fascinated with the ocean as a child and developed an interest in art. After earning a degree in Experimental Animation at the California Institute of Arts in Valencia, he went on to work in television as a director and writer on Nickelodeon’s series “Rocko’s Modern Life.”